Use 'override/final' instead of 'virtual' for overridden methods

The patch is generated using clang-tidy misc-use-override check.

This command was used:

  tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py \
    -checks='-*,misc-use-override' -header-filter='llvm|clang' \
    -j=32 -fix -format

http://reviews.llvm.org/D8925



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234679 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachinePassRegistry.h

@@ -124,7 +124,7 @@ class RegisterPassParser : public MachinePassRegistryListener,
 public:
   RegisterPassParser(cl::Option &O)
       : cl::parser<typename RegistryClass::FunctionPassCtor>(O) {}
-  ~RegisterPassParser() { RegistryClass::setListener(nullptr); }
+  ~RegisterPassParser() override { RegistryClass::setListener(nullptr); }
 
   void initialize() {
     cl::parser<typename RegistryClass::FunctionPassCtor>::initialize();